YES.....
Electric element is a 'submersion' element. Needs water to absorb heat generated otherwise element burns out.
Propane can be used regardless as it is a separate heating system
If PROPANE is turned on w/o water......the normal t-stat AND High temp t-stats will both open due to tank getting heated. (No melting will happen)
As long as water is NOT turned on allowing water to flow into HOT tank it will be OK.......just let it cool down.
Hot Suburban WH Tank (glass-lined) and COLD water ------ shattered lining
Electric and propane can be used at same time for faster heat recovery
Suburban uses different sets of -t-stats for electric and for propane so even if one set t-stats is bad the other heating source can be used.
Atwood (since 2004 models) uses ONE set for electric/propane so if t-stat is issue NO heating source can be used